Dental appliance.



E. R. STEALY.

DENTAL APPLIANCE.

APPLIOA'YION FILED r111z.2.1911.

Patented Deo. 1, 19121 El l) showing the investment therein.

ELYA. it. STl'RilLY, 01T SHENANDOAH, IOWA.

:DENTAL APPLIANGE.

t ai @im tl we Specification ot Letters Patent.

atented Dec. il, tutt.

Application filed February t28, 1911. Serial No. 611,468.

To all fic/'tom it may concern lle it known that l, lLZA R. Srnufr, citi-` ol. the tlnited States, residing at Shenandoah, in the county of Page and State oit iowa. have invented certain new and useful improvements .in Dental Appliances, of which the following is a specification.

tdy invention relates to dental apparatus and more particularly to apparatus primarily designed for dental casting.

The invention relates to the investment cups and flasks Within which the casting is made.

'.lhe primary object or' my invention is to priivide means whereby the investment material disposed within an investment cup may be submitted over a large portion ot' its surface to the action of a vacuum (it a vac u um is beingl used 'for casting) and in connection therewith to provide `investment rings or lasl's, each having an .airtight engagement with the investment cup but so constructed as to present a relatively large surface to the action of the vacuum.

A further object is to improve the construction oi2 the investment cup and the investment ringI or flask', so as to permit the cup and flask to be used in many dillerent ways :for dill'erent forms of casting.

lilly invention is illustrated in the accompanying drawings wherein:

Figure l is a longitudinal diametrical section through an investment cup, this figure Fig. 9. is a like section to F ig. l, but showing the investment placed Within an investment ring. Fig. 3 is a like View to Fig. 2 but showing another manner of engaging the investment ring or flask with the investment cup. Fig. l is a longitudinal diametrical section oit' a flask or investment ring. Fig. 5 is a like viewto Fig. Il but showing another form of investment ring or flask. Fig. 6 is a longitudinal diametrical section of an investment cup, a supplemental ring and an investment ring or flask, this having the form ot' the ring shown in Fig. l.

My improved investment cups are intended .to be used with. a vacuum chamber to which the cups are connected by means ot' a connecting tube in amanner so well known in the art' as not to need 'further description, and the details ot' lthe vacuum appara tus need not be stated as vacuum chambers for this purpose are also well known in the art and my investment cup and ring or tlask may be used with any desired vacuum cl1amber.

For the purpose ot supporting the investment in proper relation to the vacuum ap paratus, .l provide un investment cup 1T, such asthat illustrated in Fig. l. This investrnent cup is either round or oval. the round cup being used :tor casting relatively small articles. The cup is provided with a slightly tapering body, the internal surface ol which is ground or otherwise formed so as to provide an airtight joint with an invcstment ring to be later described. The external surface oi the cup is also ground, for a purpose to be later described.

The lower end ole the cup is ilormed with a` tapering stem 18. The bore ol this stem I nelerably tapered reverscly to the cX- terior of the stem, that is, it contr-.iets in diameter from the end ol: the stem toward the body oit the cup, and the interior tace oi the bore is ground. The exterior lace ot' the stem is also ground so that the stem may be inserted within the tapering end 18 ot' a tubo 9 and will iorm an airtight ground joint therewith. This tube. 9 connects to a vacuum chamber, not shown. The bottom oi? the investment cup surrounding the central bore el the stem is llat as at 18 and ground so as to it'orm anair-tight joint with the ground bottom ol ring, as will be later described.

As a means `for supporting the investment within the investment cup and permitting the investment to be readily inserted or \\'ithdrawn therefrom, and further to per mit the investment to be submitted to the action of the vacuum over a relatively large surface, I provide an investment ring such as shown in Figs. Q to 6 and designated 23 in Fig. 2 and 23 in Fig. l. lhis ring or llask has a slightly tapering body portion adapted to t snugly in Ythe interior ot' the investment cup, the outer face of the body portion being ground where it contacts with the inner 'face oi the investment cup so as to form an airtight joint therewith. The bottom ol' the investment ring or llask in the vform oi investment ring shown in Figs. Q and 3 is lormed with an annular seat and has a central depres 2d portion formed with a central opening 22 in Fig. 2 or openings 2Q in Fig. 3.

ln Fig. i). the investment ring or ilask 23 is ot" such size relative to the investment cup: that it will fit within the upper poran investment (Sli air-tight joint therewith.

tion of the investment cup, lout will not eirtend to the bottom of the cup, so that an air space is left between the bottoni of the cup and the bottom of the investment ring. The exterior face of the investment ring 23 is ground so as to form an air-tight joint with the ground interior face of tlie cup l?.

As shown in F ig. 3, the investment ring is formed with a relatively i'lat annular margin 2t which is ground upon its exterior face so as to rest upon the ground bottoni 1S ot the investment cup liand form an This permits an investment' ring to be used with an investment cup considerably larger than the diameter ot the investment ring 'as shown in Fig. 3. The ring in that case rests upon the bottom of the investment cup and makes an air-tight joint therewith. 'the sides of the investment ring shown in Fig. 2 are imperforate, and this imperforate investment ring is preferably used for casting bridges oiiother relatively large castings, as there is no danger in using this ring,of placing the end of the wax form too near the perforations in the side of the ring as there would be were the investment of such castings made in the rings shown in. lliigs. l, and G, to be later described.

ln Fig.' All show another form of an investment ring, so designed as to provide an increased area for the action of the vacuum upon the investment material. ln this form of the invention the investment cup 30al is provided with a plurality of vertical slots 3l 'terminating at their upper4 ends in enlarged openings 82. llt will be seen that when this ring is placed within the cup as in lig. 6, the slots 3l opening as they do at the bottom of the ring and extending upward as they do along the outer face of the investing material, will provide for the withdrawal of air through the side of the investing material as well as through the bottom thereof. ln 'this form of the bottom is perforated.

ln Fig. 5 l 'show still another form of investment ring embodying my invention and very similar to the ring shown in lT ig. 4c. 'lhe wall of the investment ring 30 near its lower end is provided with a plurality of perforations 83 which connect with the vertically disposed grooves S-l extending down on the exterior face of the wall ot the. investment ring and opening the lower end thereof. this form of investment ring when placed within an investment cup will afford a plurality of peripheral passages between the outerface of the ring and the inner face of the investment cup by which air may be withdrawn from around the side of the investing material as well as through the lower end thereof. il have found iii practice that the two forms of investment rings llt will be obvious that laat/e shown in Figs. l and 5 are particularly eliective. Y,

ln llig. 6 ll show a number of investment rings supported one inside of another within an investment cup, thus providingrmeans whereby a relatively small investment ring may be used with a relatively large investment cup. .lt will be seen that this manner ot using the investment rings is rendered possible by the exterior and interior faces of the investment rings being ground and by the fact that theinterior face of the investment cup is ground. l

ln llfig. t3, il' designates the investment cup of the form heretofore described, 38 an investment ring preferably formed without a bottom, and 30 designates a relatively small investment ring such as that shown in F ig. l supported in the lirst named investment ring. i

ln .Fig l the investment cup is shown as filled with investment material. Before the investment material in its plastic form is placed within the cup, a slip of paper 25 is disposed over the opening of the cup, this slip being afterward burned away. ln Figs. '2 and 3 the investing material is shown as being disposed within the investment rings or flasks. 'llhe process of investing the casting is well known and therefore requires no special description. lt is pointed out, however, that the investment material after it hardens being porous and the area of the surface for the vacuum being relatively large, the molten metal will be drawn immediately into the cavity left by the inlay or pattern and forced into every portion of said cavity, thus securing an accurate and effective reproduction in metal of the pattern.

' rlhe process of casting is particularly well carried out by the form of cups shown in Figs. d, 5 and 6 as here the side of the investment is subjected to the action of the vacuum as well as the bottom yby reason of the slots or grooves and the perforations in the side walls of the investment flask or ring.

Having thus described the invention what is claimed as new is:-

i. l dental appliance of the character described, including` a receptacle consisting of a bowl-shaped body having a tapering stem, the exterior and interior of the stem being ground, and the interior face of the body being ground.

.2. A dental appliance of the character described, including a receptacle consisting of a bowl-shaped lbody having an exteriorly tapering stem, the interior of the stem being reversely tapered to the exterior thereof, the exterior and interior faces of the stem being ground.

3. A dental appliance of the character described, including a receptacle comprising `a bowl-shaped body having a tapering tubuthe ring having an opening, that portion of the ring' surrounding the opening being flat land ground upon its face to form an airtight joint with the bottom 'of the body:

5. A dental casting apparatus including a hollow body opening at opposite ends, and a flask contained within the hollow body and having an air-tight engagement therewith, the lower end of the flask being formed with longitudinally extending cutaway' portions opening at the lower end of the flask.

6. A' dental casting appliance, a hollow body open at opposite ends, and a flask contained within the' hollow body, the exterior face of the flask having an air-tight joint with the interior face of the hollow body,

one end of the flask being lorined with longitudinally extending grooves opening at the bottoni of the flask.

7. A dental casting appliance, a hollow body open at opposite ends, and a flask contained within the hollow body, the exterior faee ol' the flask having an airtight engagement with the interior laee of the hollow body, the exterior face of the flask at one end being longitudinally grooved, said grooves terminating in perforations, extend ing into the internal face of the flask.

8. A flask for dental investments coinprising a tapering annular body and formed adjacent one end with longitudinally extending passages, each opening at one end at the end ol the flask, the other end of each passage communicating with a radially extending perforation in the flask wall.

In testimony whereof, I affix my signature in presence of two witnesses.

i ELZA. R; STEALY. [1.. 9.]

Witnesses:

lV. J. SEELEY, E VS. SATTERLEE. 

